Energy efficiency is the primary means to achieve our climate and emission goals. Every kWh wasted is one too much.This course communicates how to achieve efficiency in the energy system by working with dedicated methods. The first step is typically to define goals and to quantify the efficiency targets. This differs from country to country and between sectors and also depends on the stakeholders (governments, city administration, industrial company, etc.). Once goals are clear, it is needed to get Information. A system can only be improved if the details are known and understood. Getting the required information involves energy metering, sensor networks, database access, municipal registries, business data, supply chain and manufacturing execution systems and other sophisticated sources of data. The heterogeneity of the data requires pre-processing before it can be used for benchmarking or KPI purposes.After the data is converted into information it needs to be visualized, correlated, and communicated to the stakeholders. This course will cover the basic methods to accomplish this.Stakeholders that are informed and motivated to improve efficiency will then implement measures. The classical way to improve efficiency is to replace old, inefficient equipment (e.g. windows, machines, insulation) with new, better ones. Additional to that, controls have a large influence on the efficiency of individual equipment and entire systems. Implementing improvement measures is not the last step. An entire, and recurrent, process of managing efficiency measures must be implemented. Periodic measurements are needed to verify the success of the measures and to adjust settings that are not ideal.